A stator is an essential component of a turbine, wherein the stator comprises vanes guiding a driving fluid of the turbine onto blades of a rotor of the turbine thereby leading to a rotation of the blades and thus the rotor. The rotation axis of the rotor defines an axial direction. A radial direction and a circumferential direction are each defined in relation to the axial direction. The vanes of the stator are arranged in rows, wherein each row usually comprises circumferentially neighbouring vanes. Said vanes usually comprise an airfoil being arranged on an inner diameter platform of the vane and at the inner end of the airfoil, wherein the term inner is defined with respect to the radial direction.
In the case of a gas turbine the driving fluid is an expanding gas, wherein the expansion is achieved by the combustion of said gas. Therefore the vanes of the stator are exposed to high temperatures, which results in a high thermodynamic stress of the vanes. In order to reduce said stress vanes usually comprise a channel system for cooling the vane with cooling gas thereby using said cooling gas to also cool the inner diameter platform, that is, the channel system is connected to a cavity of the inner diameter platform, wherein said inner diameter platform cavity is, in particular, delimited by side walls of the corresponding inner diameter platform. The term, ‘side wall’, is thereby defined with respect to the circumferential direction, wherein the side walls of the inner diameter platform each face a side wall of the inner diameter platform of a circumferentially neighbouring vane. Considering the arrangement of the vanes of the stator, this leads to a gap between the facing side walls.